2.25 kW Power-Dummyload with Heat-Spreader and Water Cooling

Рет қаралды 37,762

6 жыл бұрын

this dummyload is used for developing and testing high power LDMOS RF-amps. It handles ober 2kW power up to the 6m band. It is very small because it uses water cooling (only 200x120x10mm).
www.dj0abr.de

Пікірлер: 50

@stephenbamford 6 жыл бұрын

A very impressive display of some great engineering and lots of great 'know how'. Thanks for sharing.

@ElektronikLabor 5 жыл бұрын

Eine sehr schöne Last! Gute Idee, die Widerstände gebraucht zu bestellen!

@anandarochisha 4 жыл бұрын

Very nice Precision work. Bravo.

@user-qo5do8fi9o 4 жыл бұрын

Thank you very much for this serie of video! You've done the great work!

@williammiller5490 6 жыл бұрын

This is an awesome design and tails nicely with the amp as well. Thanks so much for your efforts. I can't wait to get started on mine for my KX3 foot warmers. Thanks again. Bill / WB9FFG

@deinprinz1 6 жыл бұрын

Great project and super explained

@user-qo5do8fi9o 4 жыл бұрын

1) copper and aluminium is not the best pair, especially with water nearby. 2) what about the drops of solder inside the channels: it will make resistance to water flow. 3) I'd also recommend making additional fixture to the resistors with screws and bars, just in case, so if anything goes wrong, the resistors would not dropped out, but internal resistors structure will anyway be melted, so now I think, no need to do it.

@ng7m-ham-shack 5 жыл бұрын

Excellent Video and Engineering! Amateur Radio at it's finest, building and engineering your own gear. 73 de Max NG7M

@fnordist 6 жыл бұрын

Gute Arbeit Scotty!

@daleburrell6273 4 жыл бұрын

VERY NICELY DONE- AND YOUR ENGLISH IS QUITE GOOD!!

@kevinkang4308 5 жыл бұрын

Very nice dummy load. Can I have a look at the water pump and bottles?

@k5azebud988 6 жыл бұрын

Very nice project, well done...

@cryscrystiii7023 3 жыл бұрын

👍 Best jobs! I would have connected in cross the resistors to a minimum inductance and plug would come in the center of the radiator.

@ComandoRebelles 4 жыл бұрын

Very good project , I learned a lot. Thanks for show us. 73.

@ernstvielsmaier9052 6 жыл бұрын

nice video, thank you for the good work

@-costas-balasoppulos5840 5 жыл бұрын

Nice job sir. Balasopoulos Kostas Greece

@RC-Heli835 2 жыл бұрын

This is very nice! Why could you not place a gasket in between the soldered plates and screw them together instead for easy maintenance? Car water pumps do it every day for years and years they work.

@michaelnobibux2886 6 жыл бұрын

These resistors usually have limited voltage ratings , so the amp must be very well matched to 50 ohms! Also dissimilar metals in the presence of cooling water is a recipe for corrosion! Take care!!

@ne2i 5 жыл бұрын

The water is in the copper side. The aluminum does not touch the water. Its just a cover plate

@wisehomo 2 жыл бұрын

hhh I think you love your water cooling invention you keep good work. I love your work.

@northbetrue 5 жыл бұрын

Brilliant!

@sbreheny 4 жыл бұрын

Did you clean out the flux from the cooling channels after soldering?

@ghlscitel6714 Жыл бұрын

Nicht schlecht, Herr Specht!

@guoss7741 Жыл бұрын

Connecting 9 resistors like this will affect the inductance or not.

@user-ww6pb7rj5s 3 жыл бұрын

recommended feed Power is 2250w for ssb mode only but fm /cw mode is half power reduce , because resistor temp over then 150 degree ( resistor failue)

@doug8085 3 жыл бұрын

So, no radiator in water circuit? Think something like a computer water system would be much help here.

@og2xradio898 3 жыл бұрын

Nice

@zeljkoadzic1692 Жыл бұрын

is this really 750 W continuous load?

@JamesJohnson-ny3xz 5 жыл бұрын

VERY COOL, 😁.

@richardnanis 5 жыл бұрын

How do you solder these resitors on this massive block of copper??? You need a few kW soldering iron or gas burner for that. Ahh - i see the kitchen stove did the work :-)

@harry4516 5 жыл бұрын

right, hi. Most important is to give a few bucks to your wife for shopping. If she left home, you go into the kitchen and heat up the copper block until the solder melts. This is a critical temperature because the ceramic case of the resistors will start floating when the solder is melted and therefore must not be touched.

@muckemark4318 9 ай бұрын

woher bekommt man so einen guten wiederstand für sowas selber zu bauen? und wievil braucht man dazu? wäre super wenn man das erfahren könnte.

@hamshallofshame9890 2 ай бұрын

Entweder Du hast das Video nicht wirklich angeguckt oder Dein Englisch ist so schlecht wie mein Mandarin.

@brucetraudt1571 5 жыл бұрын

you selling these??

@MrRichard57000 6 жыл бұрын

so if i use one resistor it s should handel 200-250 watts for a minute??(for 11 meter band)cool video btw.....

@harry4516 6 жыл бұрын

yes, it handles 200 watts for long time. The water cooling is very effective. But the resistor must be "soldered" to the copper.

@MrRichard57000 6 жыл бұрын

yes oke,i orderd 4 resistors (with one connector) and want too use 2 rows parralel and then connect them in serie(of course with some kind of insulation?)..in this case can we handel one kilo watt??thanks for your feed back!!!

@harry4516 6 жыл бұрын

Resistors with one connector are a problem because you need insulation. Better to use resistors with two connectors and solder it directly on the copper plate. In my first version I tried it with insulation, but the resistor burned. You get 50 ohms / 250 watts resistors with two connectors easily from aliexpress for low price. You can also use two resistors with two connectors and two resistors with one connector, which gives you a very good ground connection.

@MrRichard57000 6 жыл бұрын

yes oke,i saw those with the double connection...believe it ore not but shippmant too the Netherlands was 60 euro and too Germany 1,74 euro....i m going to make a smale one with one resistor(only for 200 watts and a few seconds).and will order those with the double connection and let them ship too my german collega....thanks for the info harry...

@sudriyodriyo8557 2 жыл бұрын

Resistor 2 kaki belinya dimana??

@rogeronslow1498 5 жыл бұрын

Those resistors are not designeg to be soldered to a heatsink. You may damage them.

@harry4516 5 жыл бұрын

yes you are right, its a big risk. If they get touched during soldering they are damaged. But if we are very careful the cooling is very nice.

@andrephilipp23 6 жыл бұрын

very COOL ;- ) 73 de OE8ASR

5 жыл бұрын

It is very nice project! Ha7nk

@robmccance 6 жыл бұрын

Harry - you sure like the water cooling!! Nice work. Here's a similar air-cooled dummy load I made back in June: www.qrz.com/db/N4GA Bottom of the page. Take a look! Rob

@harry4516 6 жыл бұрын

Rob, your dummyload looks really cool, but what ??? I see 25 resistors, 250 watts each. 25 * 250 = 6250 woww :-)

@LB3HC 6 жыл бұрын

Harry, where can I find your e-mail address?

@hickenc2187 2 жыл бұрын

자세히는 못 봤는데 ㅎ 내부에 물과 반응하지 않는 코팅을 했나? 안 했나? 예를 들어서, 수산화알루미늄은 잘 자랍니다.. 금속은 다 그러함. 수냉방식 펠티에냉장고 만들어 보니 그렇더라구요. 가공하실 분 참고를 하소서. 그리고 원터치피팅은 기체용도임 그 구조와 리테이너의 재질상 액체용도로 쓰면 단명함. +덕분에 공정 잘 보았고 대단히 고맙습니다.

@hickenc2187 2 жыл бұрын

I didn't look closely, but is there a coating on the inside that doesn't react with water? didn't you? For example, aluminum hydroxide grows well. All metals do. It was like that when I made a water-cooled Peltier refrigerator. Please refer to the person who is processing. And one-touch fittings are for gas use. Due to their structure and retainer material, they are short-lived when used for liquid applications. +Thank you, I saw the film and thank you very much~~~ !!!!